Web traffic cleansing

Hello,

I hope this is the right group to help with my query, apologies if it's
not.

I am looking for a device or software that will inspect and clean
malicious or malformed url's from web requests.  Ideally I'd like a
device that can run with a second chassis for resilience as it has to
operate in a high availability environment.
tail.  (We already have firewall etc)

Any recommendations gratefully accepted. 

Many thanks,

Steve